First time using a quote so hope this works...

Looking at the wire diagram on Toyota's tech website, it looks like they're no longer using PWM to reduce brightness of the high beams when in DRL mode. Instead, they're just running the two bulbs in series which cuts the voltage in half and reduces the brightness. Not sure how the Xtreme LED driver works, but maybe it was looking for the PWM and since it's not seeing that in the '21s it's running at full brightness.

Don't want to steer you one way or the other in case I'm wrong, but look at which models the headlight applies for. The more expensive one looks like it's applicable to the models which have dual-high and low-led projectors: Nightshade, Limited, and Pro. Not sure what the canadian one is for, but it might not have the dual-high/low LED projector.

Anyone with a '21 Limited, Nightshade, or TRDPro willing to take some voltages for the wires going into the low beam connector on the headlights?

I've been digging through the wiring diagrams and repair manuals on https://techinfo.toyota.com/ and I think I've figured out how the '21 lights work. Only thing I'm not sure about is the voltage that the ECU is supplying to the low/high beam LED module and the solenoid for the low/high projector shade.

There should be wire loom with 3 wires going into a 4 wire socket on the headlight. I think the wire colors are Red, Blue, and Black. While the truck is running (engine on, but in Park), I'd like to know the voltage of:

Low Beams On:
Red to Black voltage
Blue to Black voltage

High Beams On:
Red to Black voltage
Blue to Black voltage

Please don't do this unless you're comfortable testing wire voltages. Don't wreck your truck or hurt yourself.

I think the voltages should be around 12 Volt, but there's a new LED driver module in the '21 ECU that supplies this current so I'm not sure if it's 12 Volt or a little higher like 14 or 15. For retrofitting these headlights to an older truck we'd want to match this voltage to get full brightness out of the LEDs, but also not over drive them and burn them out.

Once I finish figuring out the wiring for the new lights and how to retrofit them on an older truck I'll post some info here.

There might even be potential for '21 models without the bi-low/high LEDs to make them bi-LED, but to know that we'd need more photos of the wiring on these models. It might be a long-shot, but the lights could be wired for the bi-LED function from the 4-wire plug to the projector, but not be using the solenoid wire which is what needs to be activated to move the high beam shade up for high beam mode.

Haha, I am doing the same. I guess it’s a race to who does them first at this point. lol I was one of the first to retro stock Lexus hids to a 95 accord back in 98. lol good luck. To the best man wins!

I'm in for a set.

I think you are right on - only one of those has LED for high and low beams, so presumably that's the one you want.

Canada has different laws around DRLs, so if you don't live in Canada, prob want to stear clear from that one.

Update on that for people that chimed in. I've talked to three separate people that either have made harnesses for Taco LED retrofits or that made other wiring harnesses and there was some interest but no evidence of doing anything about it any time soon.

So looks like our friends @PLRBRR and @Axix23 represent our hopes and dreams on this one.

I'm totally happy to help experiment w my vehicle (2019).

Glad I'm not the only one crazy enough to jump into this mod! I've done this sort of thing before too, swapped '05 WRX STi HID headlights into my '05 WRX. That was pretty straightforward, but required a few relays to get 12v, non-DRL-reduced voltage to the HID ballasts. Glad to say they still work great.

Update on '21 lights:

I picked up my lights from Toyota last night and from my initial look it seems like these are going to be an easy swap other than the wire harness. Haven't penned out the harness wiring yet, but should have it done this week. I'd love a plug and play harness from one of the guys that did the Tacoma lights, but with a couple relays, wire loom, conduit, OEM connectors, and electrical tape we should all be able to make a retrofit harness pretty easily.

Still would like to know if the '21 supplies regulated 12v or if it's a floating voltage like 14 or 15 that's straight from the battery/alternator. If anyone with a '21 is willing to test their voltages based on my earlier post we would all be really grateful!

Also, I found a couple YouTube videos of a '20 Camry headlight breakdown and testing that I think is at least similar if not the same as the '21 4Runner lights. One of the cons with these lights is the price and difficulty in replacing the LED projector/light module if the LED burns out for some reason. So, seeing that it might be possible to replace the projector down the road is at least a little reassuring. I can definitely understand the comments from others that the non-replaceable LED light is a no-go for them. It bugs me too, but I'm hoping the better light output will make all the hassle and expense worth it.

Disassembly of '20 Camry Headlights:
2019-2021 Toyota Camry LED Headlight Disassembly - YouTube

Testing of '20 Camry Headlights:
How to test a 2018-2020 Toyota Camry OEM LED Headlight - YouTube

If I may ask, how much did the lights run you?

That's definitely a con compared to a simple bulb replacement, but the alternative is either LED retrofits that have crap projection, aftermarket headlights like the Morimotos that are of questionable quality and aren't user serviceable either, or full on retrofits that cost a ton and in my opinion look out of place.

I'm hoping for a "professional" harness not because I can't solder or follow instructions but because I know that someone else is going to produce a nicer product and I don't have the time to screw around with it. Hopefully y'all figure this out soon and we can all reap the benefits. Keep up the good work!

Mine were about $750 each side, but you can find them closer to $700 from other dealers plus shipping. If you can find a local dealer that sells parts online you can usually get a good below-list price and then do local pickup and not pay shipping, that's what I did.

I think your issue is specific to the 4Runner, not Toyota.

We've had a Prius v and Highlander with LED headlights. No dead spot.

I just got mine too. I have one temporary wired up and lights up just fine. The harness needs to be modified alittle but I used push connectors temporary to test them out.

Will post photos when I get a chance.

Would be great to see some proper OEM LED headlights made available for older 4Runners. Way better than any of the aftermarket junk swaps.

I'm interested in a harness.... shoot, if someone can figure out what's needed, I may be able to help source the parts needed.
The only other issues is the lights themselves LOL